In Windows, we cannot delete a file that has been opened.
We use this feature to "lock" the pidfile.
Signed-off-by: Gurucharan Shetty <gshe...@nicira.com>
---
lib/daemon-windows.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
lib/daemon.h | 8 ++++-
2 files changed, 86 insertions(+), 1 deletion(-)
diff --git a/lib/daemon-windows.c b/lib/daemon-windows.c
index baa7520..b47b42e 100644
--- a/lib/daemon-windows.c
+++ b/lib/daemon-windows.c
@@ -34,6 +34,9 @@ static bool detach; /* Was --detach specified? */
static bool detached; /* Running as the child process. */
static HANDLE write_handle; /* pipe handle to write to the parent. */
+static char *pidfile; /* --pidfile: Name of pidfile (null if none). */
+static FILE *filep_pidfile; /* File pointer to access the pidfile. */
+
/* Handle to the Services Manager and the created service. */
static SC_HANDLE manager, service;
@@ -409,10 +412,59 @@ daemon_save_fd(int fd OVS_UNUSED)
void
daemonize(void)
{
+ daemonize_start();
+ daemonize_complete();
+}
+
+static void
+unlink_pidfile(void)
+{
+ if (filep_pidfile) {
+ fclose(filep_pidfile);
+ }
+ if (pidfile) {
+ unlink(pidfile);
+ }
+}
+
+/* If a pidfile has been configured, creates it and stores the running
+ * process's pid in it. Ensures that the pidfile will be deleted when the
+ * process exits. */
+static void
+make_pidfile(void)
+{
+ int error;
+
+ error = GetFileAttributes(pidfile);
+ if (error != INVALID_FILE_ATTRIBUTES) {
+ /* pidfile exists. Try to unlink() it. */
+ error = unlink(pidfile);
+ if (error) {
+ VLOG_FATAL("Failed to delete existing pidfile %s (%s)", pidfile,
+ ovs_strerror(errno));
+ }
+ }
+
+ filep_pidfile = fopen(pidfile, "w");
+ if (filep_pidfile == NULL) {
+ VLOG_FATAL("failed to open %s (%s)", pidfile, ovs_strerror(errno));
+ }
+
+ fatal_signal_add_hook(unlink_pidfile, NULL, NULL, true);
+
+ fprintf(filep_pidfile, "%d\n", _getpid());
+ if (fflush(filep_pidfile) == EOF) {
+ VLOG_FATAL("Failed to write into the pidfile %s", pidfile);
+ }
+
+ /* Don't close the pidfile till the process exits. */
}
void daemonize_start(void)
{
+ if (pidfile) {
+ make_pidfile();
+ }
}
void
@@ -431,3 +483,30 @@ daemonize_complete(void)
service_complete();
}
+
+/* Returns the file name that would be used for a pidfile if 'name' were
+ * provided to set_pidfile(). If 'name' is not provided, returns the default
+ * name based on rundir. The caller must free the returned string. */
+static char *
+make_pidfile_name(const char *name)
+{
+ if (name && strchr(name, ':')) {
+ return strdup(name);
+ } else {
+ return xasprintf("%s/%s.pid", ovs_rundir(), program_name);
+ }
+}
+
+/* Sets up a following call to daemonize() to create a pidfile named 'name'.
+ * If 'name' contains ':', then it is treated as an absolute path.
+ * Otherwise, it is taken relative to RUNDIR, which is $(prefix)/var/run by
+ * default.
+ *
+ * If 'name' is null, then program_name followed by ".pid" is used. */
+void
+set_pidfile(const char *name)
+{
+ assert_single_threaded();
+ free(pidfile);
+ pidfile = make_pidfile_name(name);
+}
diff --git a/lib/daemon.h b/lib/daemon.h
index f4dced3..0b7dc5f 100644
--- a/lib/daemon.h
+++ b/lib/daemon.h
@@ -74,19 +74,20 @@
void set_detach(void);
void daemon_set_monitor(void);
-void set_pidfile(const char *name);
void set_no_chdir(void);
void ignore_existing_pidfile(void);
pid_t read_pidfile(const char *name);
#else
#define DAEMON_OPTION_ENUMS \
OPT_DETACH, \
+ OPT_PIDFILE, \
OPT_PIPE_HANDLE, \
OPT_SERVICE, \
OPT_SERVICE_MONITOR
#define DAEMON_LONG_OPTIONS \
{"detach", no_argument, NULL, OPT_DETACH}, \
+ {"pidfile", optional_argument, NULL, OPT_PIDFILE}, \
{"pipe-handle", required_argument, NULL, OPT_PIPE_HANDLE}, \
{"service", no_argument, NULL, OPT_SERVICE}, \
{"service-monitor", no_argument, NULL, OPT_SERVICE_MONITOR}
@@ -95,6 +96,10 @@ pid_t read_pidfile(const char *name);
case OPT_DETACH: \
break; \
\
+ case OPT_PIDFILE: \
+ set_pidfile(optarg); \
+ break; \
+ \
case OPT_PIPE_HANDLE: \
set_pipe_handle(optarg); \
break; \
@@ -117,6 +122,7 @@ void daemonize_complete(void);
void daemon_usage(void);
void service_start(int *argcp, char **argvp[]);
void service_stop(void);
+void set_pidfile(const char *name);
bool should_service_stop(void);
#endif /* daemon.h */
--
1.7.9.5
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
